Chemical mechanical polishing system

Abstract

The application discloses a chemical mechanical polishing system, which comprises a preposition unit, a polishing unit and a cleaning unit arranged between the preposition unit and the polishing unit, wherein the cleaning unit comprises a first cleaning unit and a second cleaning unit, the first cleaning unit and the second cleaning unit are symmetrically arranged relative to a transverse center line of the cleaning unit, the first cleaning unit and the second cleaning unit comprise rear treatment modules arranged in a horizontal and vertical staggered mode, the rear treatment modules close to the transverse center line are arranged in a multi-layer and vertical stacking mode, and the rear treatment modules close to the side of the cleaning unit are arranged in a single layer, and the system further comprises a transmission manipulator which is arranged close to the rear treatment modules and symmetrically arranged on both sides of the transverse center line.

Description

Technical Field

[0001] This invention belongs to the field of chemical mechanical polishing technology, and more specifically, relates to a chemical mechanical polishing system. Background Technology

[0002] The integrated circuit industry is the core of the information technology industry, playing a crucial role in promoting the digital and intelligent transformation and upgrading of the manufacturing industry. Chips are the carriers of integrated circuits, and chip manufacturing involves processes such as integrated circuit design, wafer fabrication, wafer processing, electrical measurement, dicing, packaging, and testing. Among these, chemical mechanical polishing (CMP) is one of the five core processes in wafer fabrication.

[0003] Chemical mechanical polishing (CMP) is an ultra-precision surface processing technology that achieves global planarization. A CMP system typically includes a front-end unit, a polishing unit, and a cleaning unit. Through chemical mechanical polishing, wafers that meet process requirements can be obtained.

[0004] Since the functions of the pre-cleaning unit and the polishing unit are relatively fixed, while the process of the cleaning unit is more complex, involving pre-cleaning, brushing, drying and other procedures; the various modules in the cleaning unit are arranged in a relatively close manner, especially requiring electrical and hydraulic components, which seriously reduces the maintenance space of the cleaning unit, which is not conducive to operators carrying out normal maintenance work. Summary of the Invention

[0005] This invention provides a chemical mechanical polishing system, which aims to at least solve one of the technical problems existing in the prior art.

[0006] A first aspect of the present invention provides a chemical mechanical polishing system, comprising:

[0007] Front unit;

[0008] Polishing unit;

[0009] The cleaning unit is located between the pre-processor unit and the polishing unit;

[0010] The cleaning unit includes a first cleaning unit and a second cleaning unit, which are symmetrically arranged with respect to the horizontal center line of the cleaning unit. The first and second cleaning units include post-processing modules arranged in a crisscross pattern, with multiple layers of post-processing modules near the horizontal center line stacked vertically and a single layer of post-processing modules near the side of the cleaning unit. The unit also includes a transfer robot, which is arranged adjacent to the post-processing modules and symmetrically on both sides of the horizontal center line.

[0011] In some embodiments, the vertical height of the post-processing module near the side of the cleaning unit is the same as the vertical height of the post-processing module above the horizontal center line.

[0012] In some embodiments, the chemical mechanical polishing system further includes a buffer mechanism located between vertically stacked post-processing modules.

[0013] In some embodiments, the caching mechanism is further disposed below the post-processing module near the side of the cleaning unit.

[0014] In some embodiments, the caching mechanism is disposed below the post-processing module adjacent to the front unit.

[0015] In some embodiments, the first cleaning unit is configured with a pair of transfer robots, one of which is located near the front unit and the other is located near the polishing unit.

[0016] In some embodiments, the transfer robot is configured with a vertical slide rail that allows it to move vertically to transfer wafers between adjacent post-processing modules.

[0017] In some embodiments, the post-processing module includes a brushing module, a pre-cleaning module, and a drying module, which process the wafer surface in a horizontal manner.

[0018] In some embodiments, the drying module is disposed adjacent to the front unit.

[0019] In some embodiments, the post-processing module is provided with a switch door on its side, the switch door being positioned toward the transfer robot.

[0020] The beneficial effects of this invention include:

[0021] a. The post-processing modules operate independently and do not interfere with each other, which helps to improve the fault tolerance of the cleaning unit;

[0022] b. The post-processing modules are staggered along the horizontal and vertical sides of the cleaning unit, which increases the maintenance space of the cleaning unit and improves the convenience of using and maintaining the CMP system;

[0023] c. A single-layer post-processing module is set on the side of the cleaning unit, and corresponding electrical and hydraulic accessories are arranged below or above the single-layer post-processing module to make full use of the internal space of the cleaning unit and improve the maintainability of the equipment. Attached Figure Description

[0024] The advantages of the present invention will become clearer and easier to understand through the following detailed description in conjunction with the accompanying drawings, which are merely illustrative and do not limit the scope of protection of the present invention, wherein:

[0025] Figure 1 This is a schematic diagram of a chemical mechanical polishing system provided in an embodiment of the present invention;

[0026] Figure 2 yes Figure 1 Front view of the chemical mechanical polishing system;

[0027] Figure 3 This is a schematic diagram of a caching mechanism provided in an embodiment of the present invention;

[0028] Figure 4 yes Figure 1 Side view of the corresponding chemical mechanical polishing system;

[0029] Figure 5 yes Figure 1 A schematic diagram of the corresponding cleaning unit;

[0030] Figure 6 This is a schematic diagram of a cleaning unit provided in an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of a scrubbing module provided in an embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of a pre-cleaning module provided in an embodiment of the present invention;

[0033] Figure 9 This is a schematic diagram of a drying module provided in an embodiment of the present invention;

[0034] Figure 10 It is a route diagram of wafer transport in a chemical mechanical polishing system. Detailed Implementation

[0035] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0036] The accompanying drawings in this specification are schematic diagrams used to illustrate the concept of the invention and to schematically show the shapes of the various parts and their interrelationships. It should be understood that, in order to clearly show the structure of the various components of the embodiments of the invention, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings.

[0037] In this invention, "Chemical Mechanical Polishing (CMP)" is also called "Chemical Mechanical Planarization (CMP)," and the wafer (W) is also called the substrate (Substrate), with the same meaning and actual function.

[0038] The embodiments disclosed in this invention generally relate to chemical mechanical polishing (CMP) units used in the semiconductor device manufacturing industry. During CMP, a polishing slurry composed of submicron or nano-sized abrasive particles and a chemical solution flows between the wafer and the polishing pad. The polishing slurry is uniformly distributed under the action of the transmission and rotational centrifugal force of the polishing pad to form a liquid film between the wafer and the polishing pad. The chemical components in the liquid react chemically with the wafer, converting insoluble substances into soluble substances. Then, these chemical reactants are removed from the wafer surface by the micromechanical friction of the abrasive particles and dissolved into the flowing liquid and carried away. That is, surface material is removed in the alternating process of chemical film formation and mechanical film removal to achieve surface planarization, thereby achieving the purpose of global planarization.

[0039] Figure 1 This is a schematic diagram of a chemical mechanical polishing system according to an embodiment of the present invention. The chemical mechanical polishing system includes:

[0040] Front End Module 1, which can be abbreviated as EFEM (Equipment Front End Module), is used to store wafers to be polished and polished wafers;

[0041] Polishing unit 3 is used to perform chemical mechanical polishing to remove material from the wafer surface;

[0042] Cleaning unit 2 is located between pre-cleaning unit 1 and polishing unit 3 to remove particles remaining on the wafer surface during the polishing process, ensuring that the cleanliness of the wafer surface meets the process requirements.

[0043] Furthermore, the front-end unit 1 includes four front-opening wafer transfer pods 1a and a front-end robotic arm 1b. The front-opening wafer transfer pods 1a (FOUP) are used to store wafers. The front-end robotic arm 1b is located on one side of the front-opening wafer transfer pods 1a and is used for wafer transfer between the front-end unit 1 and the cleaning unit 2. The front-end robotic arm 1b is typically equipped with two gripping jaws, one above the other, to respectively grasp polished wafers and wafers to be polished, avoiding cross-contamination during wafer gripping.

[0044] Figure 1In the present invention, the cleaning unit 2 comprises a first cleaning unit 2A and a second cleaning unit 2B, wherein the first cleaning unit 2A and the second cleaning unit 2B are symmetrically arranged relative to a transverse center line CL of the cleaning unit 2. The transverse center line CL is arranged along the length direction of the cleaning unit 2, and is a connecting line of the midpoints of the cleaning unit 2 in the width direction. In the present invention, the transverse direction of the cleaning unit 2 refers to the length direction of the cleaning unit 2; the longitudinal direction of the cleaning unit 2 refers to the width direction of the cleaning unit 2.

[0045] Since the structure and layout of the first cleaning unit 2A and the second cleaning unit 2B are substantially the same, the composition and connection relationship of the first cleaning unit 2A will be described in detail below. For the convenience of description, the names of components in the first cleaning unit 2A start with "first", and the component numbers end with "A"; correspondingly, the names of components in the second cleaning unit 2B start with "second", and the component numbers end with "B".

[0046] The first cleaning unit 2A comprises a plurality of post-processing modules 20, and the post-processing modules 20 are arranged in a staggered manner along the transverse direction and the longitudinal direction. The first cleaning unit 2A further comprises a transfer robot 30, and the transfer robot 30 is arranged adjacent to the post-processing modules 20, so as to facilitate transferring wafers between the post-processing modules 20.

[0047] Specifically, the first cleaning unit 2A comprises four post-processing modules 20; wherein the post-processing module 20 close to the transverse center line CL is of two layers, and the post-processing modules 20 are stacked in a vertical direction; the post-processing module 20 close to the side of the cleaning unit 2 is of a single layer. That is, the single-layer post-processing module 20 and the double-layer stacked post-processing modules 20 form a "pin-shaped (Chinese character 'pin') structure, the staggered post-processing modules 20 can provide space for daily maintenance or fault repair by operators, which is beneficial to improving the convenience of use of the CMP system.

[0048] Further, the transfer robot 30 comprises a front transfer robot 31 and a rear transfer robot 32, wherein the front transfer robot 31 is adjacent to the front unit 1, and the rear transfer robot 32 is adjacent to the polishing unit 2.

[0049] Figure 1 In the present invention, the first cleaning unit 2A comprises a first front transfer robot 31A and a first rear transfer robot 32A, the stacked post-processing modules 20, the first front transfer robot 31A and the first rear transfer robot 32A are substantially located on the same straight line, and a connecting line between the positions of the first front transfer robot 31A and the first rear transfer robot 32A is parallel to the transverse center line CL.

[0050] Figure 2 is Figure 1 is a front view of the chemical mechanical polishing system, wherein the vertical height of the post-processing module 20 close to the side of the cleaning unit 2 and Figure 1 The post-processing modules 20 shown above the horizontal center line CL have the same vertical height. This configuration allows the wafer transfer robot 30 to be positioned in a relatively fixed vertical location, facilitating wafer transfer between adjacent post-processing modules 20 and improving wafer transfer efficiency in the cleaning unit 2.

[0051] As an embodiment of the present invention, the chemical mechanical polishing system further includes a buffer mechanism 40, such as... Figure 2 As shown, the caching mechanism 40 is located between the vertically stacked post-processing modules 20 to cache the wafers inside the cleaning unit 2, balance the differences in processing time between processes, and reduce process waiting time.

[0052] Figure 3 This is a schematic diagram of a cache mechanism 40 provided in an embodiment of the present invention. The cache mechanism 40 includes a cache body part 41 and a claw part 42. The claw part 42 is disposed above the cache body part 41, and there are multiple claw parts 42 to clamp the wafer W placed in the cache mechanism 40.

[0053] Figure 2 In the embodiment shown, the caching mechanism 40 is also disposed below the post-processing module 20 near the side of the cleaning unit 2 to provide a wafer caching station during wafer transfer.

[0054] Furthermore, the cache mechanism 40 is located below the post-processing module 20 adjacent to the front unit 1. The front robot 1b in the front unit 2 can place the wafer to be polished in the cache mechanism 40 adjacent to the front unit 1, so that the transfer robot 30 can transfer the cached wafer toward the polishing unit 3.

[0055] This invention abandons the existing lateral transmission mechanism (running beam) scheme and sets up a buffer mechanism 40 between or below the post-processing modules 20. This helps to simplify the wafer transmission path, reduce the size of the cleaning unit 2, reduce the space occupied by the cleaning unit, and thus reduce the footprint of the CMP system.

[0056] Furthermore, the post-processing modules 20 operate independently without interfering with each other, which helps improve the fault tolerance of the cleaning unit 2. Specifically, if one of the post-processing modules 20 fails and stops, the other post-processing modules 20 will not be affected by the failed post-processing module 20 and will continue to operate normally, thus ensuring the stability of the cleaning unit 2.

[0057] Figure 4 yes Figure 1 Side view of the corresponding chemical mechanical polishing system. Figure 5 yes Figure 1 A schematic diagram of the corresponding cleaning unit 2.

[0058] In this invention, the transfer robot 30 is also equipped with a vertical slide rail 33, such as... Figure 4 and Figure 5 As shown, the transfer robot 30 is capable of moving vertically to transfer wafers between adjacent post-processing modules 20.

[0059] Figure 1 In the embodiment shown, the chemical mechanical polishing system also includes a multi-layer buffer device 50, which is disposed between the cleaning unit 2 and the polishing unit 3 to buffer the wafers to be polished or cleaned, solve the problem of uneven processing time between each process, and ensure the operating cycle of the CMP system.

[0060] Figure 1 In this process, the multi-layer buffer device 50 is disposed in the polishing unit 3. It is understood that the multi-layer buffer device 50 may also be disposed in the cleaning unit 2; or, the multi-layer buffer device 50 may be disposed between the cleaning unit 2 and the polishing unit 3.

[0061] Figure 6 This is a schematic diagram of a cleaning unit 2 provided in an embodiment of the present invention. The first cleaning unit 2A and the second cleaning unit 2B operate independently without interfering with each other, which helps to ensure the stable operation of wafer cleaning. The post-processing modules 20 are staggered along the transverse direction of the cleaning unit 2, and are arranged vertically rather than side-by-side along the transverse and / or longitudinal direction of the cleaning unit 2. This helps to increase the maintenance space of the cleaning unit 2 and improve the convenience of CMP system operation.

[0062] Figure 1 In the illustrated embodiment, the post-processing module 20 includes Figure 7 The shown is a scrubbing module 20A. Figure 8 The pre-cleaning module 20B shown is... Figure 9 The drying module 20C shown is used to remove residual particles and chemicals from the wafer surface to obtain a clean wafer.

[0063] Figure 7 This is a schematic diagram of a brushing module 20A provided in an embodiment of the present invention. The wafer is horizontally supported by rollers and rotates under the action of friction between the rollers and the wafer edge. Cleaning brushes and liquid supply units are arranged on the front and back sides of the wafer. The cleaning brushes rotate around their axes, while the liquid supply units supply cleaning liquid to the cleaning brushes and / or the wafer surface to remove larger particles from the wafer surface, thus achieving a rough cleaning of the wafer. It should be noted that the pre-cleaning module 20A also includes a housing to ensure that the wafer surface is brushed within a relatively sealed housing.

[0064] Figure 8This is a schematic diagram of the pre-cleaning module 20B. The wafer W is horizontally clamped by multiple jaws and rotated by a rotary drive device (not shown). Further, the pre-cleaning module 20B includes a dual-fluid tube and a brush head. The dual-fluid tube sprays cleaning fluid, N2, and / or deionized water toward the wafer W to remove smaller particles from the wafer surface, achieving fine cleaning of the wafer. The brush head is positioned above the wafer via a swing arm that can oscillate around a fixed point, moving the brush head across the wafer surface to clean the tiny particles. It should be noted that the pre-cleaning module 20B also includes a housing (not shown) to ensure that the wafer pre-cleaning is performed within a relatively enclosed space.

[0065] Figure 9 This is a schematic diagram of a drying module 20C provided in an embodiment of the present invention. The wafer is horizontally clamped by claws and driven to rotate at high speed. A drying mechanism (not shown), such as a Marangoni drying mechanism, is provided above the wafer to peel off the water film on the wafer surface as a whole, thereby achieving wafer drying.

[0066] Figure 1 In the embodiment shown, the drying module 20C configured in the first cleaning unit 2A and the second cleaning unit 2B needs to be horizontally adjacent to the front unit 1 so that the front robot arm 1b in the front unit 1 can directly place the dried wafer into the front-opening wafer transfer box 1a, thereby reducing the number of wafer turnover transfers and avoiding contamination during the transfer process.

[0067] Figure 9 In this case, the drying module 20C requires a fan filter unit 20C-1 (FFU) for circulating drying gas, which is located on top of the housing. If the fan filter unit 20C-1 and the buffer mechanism 40 are installed simultaneously between the vertically stacked post-treatment modules 20, the height of the corresponding frame of the cleaning unit 2 will increase, thus increasing the vertical space occupied by the CMP system.

[0068] In this invention, the post-processing module 20 is provided with a switch door on its side, which is positioned facing the transfer robot 30 to facilitate the transfer of wafers.

[0069] Furthermore, the drying module 20C is equipped with a switch door on the side facing the front unit 1. The front robot arm 1b inside the front unit 1 can directly grab the wafer through the switch door and transfer the dried wafer to the front-opening wafer transfer box 1a of the front unit 1 to reduce the number of process turns, avoid contamination during wafer transfer, and ensure the processing quality of the wafer.

[0070] Figure 10 This is a route diagram of wafer transport in a chemical mechanical polishing system. The following is combined with... Figure 10Briefly describe the general transfer process of the wafer in the front-end unit 1, cleaning unit 2 and polishing unit 3.

[0071] Figure 10 In the illustration, the process of transferring a wafer from the pre-processing unit 1 to the polishing unit 3 via the cleaning unit 2 is described using the first cleaning unit 2A, and the corresponding transfer path is represented by a dashed line.

[0072] First, the front-end robotic arm 1b of the front-end unit 1 places the wafer to be polished into the cache mechanism 40 near the post-processing module 20 of the front-end unit 1. Figure 2 (As shown), the first step of transfer is completed; then, the first front transfer robot 31A transfers the wafer from the cache mechanism 40 below the post-processing module 20 near the front unit 1 to the cache mechanism 40 near the lateral center line CL, thus completing the second step of transfer; then, the first rear transfer robot 32A transfers the wafer placed in the cache mechanism 40 near the lateral center line CL to the multi-layer cache device 50, thus completing the third step of transfer; then, the robot in the polishing unit 3 can pick up the wafer to be polished from the multi-layer cache device 50. It is understood that the wafer can also be transferred towards the polishing unit 3 via the second cleaning unit 2B, and the two are independent of each other and do not affect each other.

[0073] Figure 10 In the diagram, the process of transferring the wafer from the polishing unit 3 to the front unit 1 via the cleaning unit is illustrated using the second cleaning unit 2B, and the corresponding transfer route diagram is represented by dashed lines.

[0074] First, the polished wafer is transferred from the multi-layer buffer device 50 to the post-processing module 20 adjacent to the polishing unit 3 by the second rear transfer robot 32B, thus completing step ④. It should be noted that the wafer can be transferred between post-processing modules 20. Next, the second rear transfer robot 32B transfers the wafer from the post-processing module 20 adjacent to the polishing unit 2 to the post-processing module 20 adjacent to the transverse center line CL, thus completing step ⑤. Next, the second front transfer robot 31B transfers the wafer from the post-processing module 20 adjacent to the transverse center line CL to the post-processing module 20 adjacent to the front unit 1, thus completing step ⑥. Finally, the front robot 1b transfers the post-processed wafer to the front-opening wafer transfer box 1a of the front unit 1, thus completing step ⑦.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A chemical mechanical polishing system, characterized in that, comprising a front unit; a polishing unit; a cleaning unit arranged between the front unit and the polishing unit; wherein the cleaning unit comprises a first cleaning unit and a second cleaning unit, the first cleaning unit and the second cleaning unit are symmetrically arranged relative to a transverse center line of the cleaning unit; the first cleaning unit and the second cleaning unit comprise post-processing modules arranged in a crisscross pattern, the post-processing modules close to the transverse center line are multiple layers and are arranged in a stacked manner along a vertical direction, and the post-processing modules close to side portions of the cleaning unit are single-layer; further comprising a buffer mechanism arranged below the single-layer post-processing module adjacent to the front unit; further comprising a transfer manipulator, which is arranged adjacent to the post-processing modules and symmetrically arranged on both sides of the transverse center line, and the transfer manipulator is provided with a vertical slide rail; the single-layer post-processing modules and the double-layer stacked post-processing modules form a "pin"-shaped structure, and the post-processing modules arranged in a crisscross pattern can provide space for daily maintenance or fault repair by operators; 2. The chemical mechanical polishing system as described in claim 1, characterized in that, the vertical height of the post-processing module close to the side portion of the cleaning unit is the same as the corresponding vertical height of the post-processing module on the upper layer close to the transverse center line; 3. The chemical mechanical polishing system as described in claim 1, characterized in that, the buffer mechanism is also located between the vertically stacked post-processing modules; 4. The chemical mechanical polishing system as described in claim 1, characterized in that, the post-processing modules comprise a scrubbing module, a pre-cleaning module and a drying module, which process the wafer surface in a horizontal manner; 5. The chemical mechanical polishing system as described in claim 4, characterized in that, the drying module is arranged adjacent to the front unit; 6. The chemical mechanical polishing system as described in claim 1, characterized in that, a side surface of the post-processing module is provided with an opening / closing door, and the opening / closing door is arranged facing the transfer manipulator;

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